Synchronizing system



1.951 v5 Sheets-Sheet l W, K. SONNE-:MANN

SYNCHRCNZING SYSTEM Filed July 23.

Oct. 9, 1934.

NN 1.. y wm @QM m@ m 0% wm Y INVENTOR M//Y//m Kbnnemann.

ATT NEY WWA/5555.

Oct. 9, 1934. y w. K. soNNEMANN 1,976,523

SYNCHRON I Z ING SYSTEM Filed July 23, 1931 5 Sheets-Sheet 2 WITNESSES rn INVENTOR h//Y//Om /.Sonneman/v.

ATTO

Oct. 9, 1934. w, K, SQNNEMANN 1,976,523

SYNCHRONI Z ING SYSTEM Filed July 23. 1951 5 sheets-sheet 3 fag 6. fig 7.' f -z'g' 8, Y Vec-fgrEobhan @afar Poaon Vcfor Eo/an- A I A I A wim/55555: INVENTOR l\/////`ar77/(.5`onnemann.

ATTO NEY Patented Oct. 9, 1934 UNITI-:D sfrlires` PATENT ori-*Ice I y 15910.52: rsrivcnaomzmo. srsrnm William xfsonnemann, Dallas, Tex., signor to Westinghouse Electric Manufacturing Company, a corporations! Pennsylvania Application July z3, 19:1, sei-ua No. 552,613

` -9 claim.. (ci. 11i-11s) ice has resulted in rapidvdevelopment of'existing and contemplated power and network systems. Greater continuity of service .has been obtained by providinga plurality of independent power sources for loop or ring systems and' network loads. In this manner the continuity of power supply is limited only by the reliability of `the prime mover at the several sources.

I'he supply of power from different sources necessitates a synchronizing function and, to insure increased emciency, the synchronizing must be effected automatically. The usual automaticsynchronizer serves to connect two power systems when the respective voltages are of the same mag- 3 nitude, in phase, and of the same frequency.

This synchronizer takes into consideration the operating characteristics of the associated circuit breaker so as to insure the closure of jthe circuitbreaker contacts only when the above conditions exist. is admirably adapted to all systems of paralleling and interconnecting of independent systems, and is more desirable, and in the majority of systems, necessary over a manually-operable scheme.

The known automatic-synchronizing systems, although they effect the desired synchronizing function, are quite expensive and require extreme accuracy in design and manufacture. It becomes apparent, therefore, that, with the newer and expanding power systems, Athe demand for some type of automatic synchronizing Aarrangement is materially increased, with the result that the expense of a suitable synchronizing devicejbecomes an important factor.

It is an object of the present invention, therefore, to provide a simplified means for'verifying conditions of synchronization rin anV electrical system; f

Another object `of the present invention is to provide a means for verifying conditions ofsynchronization" between two alternating-current sources, within a predetermined range of electrical conditions.

`Anotherobject of the present invention is rto effect the-automatic closing of a circuit breaker connected between anenergized system and adeenergized system. v

Another object'of the present invention is to Aeffect the electrical connection of two alternating-current systems, only when the magnitude,

applications.

This known synchronizing arrangement phase position, and frequency of the two system voltages Lbear ia predetermined relation.

A further object of the present invention is to eifectthe electrical connection of two alternatingcurrent systems only when the difference voltage between the two systems fallswithin a predetermined range of phase difference with respectto one of said system voltages.

A further object of the present invention is to provide a means for substantially verifying the condition of synchronization between two alterhating-current systems and for `modifying the range of verification in accordance with the magnitudes of the respective system voltages.

Further objects and advantages of the present invention will become apparent from the following detailed description of the several figures in the drawings.

It should be noted that the'present invention is not proposed as a substitute for the known synchronizing arrangements in all synchronizing For instance, in systems requiring the connecting'of two power systems only when the respective voltages are exactly equal in magnitude, phase position and frequency, the present invention will not apply and it will be necessary to employ the more expensive and complicated known synchronizingarrangements. These arrangements have the feature 'of closing ahead of synchronism at an angle of phase advance proportional to the beat frequencies and determined' by the speed of operation of the circuit breaker so that the two systems are connected exactly on synchronism The present invention does not have this feature.

The application of the present invention is quite extensive in view of the nature of many power systems, as mentioned hereinbefore. One application exists in ring or loop systems where the loads are supplied from more than one generating station and for somereason onesection of the loop has been taken out of service. Obviously there is no danger in reconnecting one end of the section by any suitable circuit-breaker reclosingsystem, but the other end of the isolatedsection cannot be reconnected unless the magnitude, phase positionvand frequency of the two system voltages are substantially the same. If the other tie or ties between the several power sources remain connected, the voltages on the two sides of the open breaker will necessarily be substantially the same in magnitude and phase position as well as in frequency, and the present invention serves to check or verify the existence of such conditions before reclosing the circuit breaker. In such applications. it is obvious that a means of exactly checking synchronism is not imperative and the simple inexpensive synchroniZinS System of the present invention may be exists, and adjustments are provided to control the magnitude of the beat frequency for which the invention will'operate to effect thev connection of the systems. The higher` the phase difference for which the device operates, the greater is the beat lfrequencyg'for which operation :is possible. The operation of the present' device with reference to the permissible beat frequency will be described in detail hereafter.

The novel design of the present invention affortisv a large application in network systems where it is mandatory that power flow vis from a feeder circuit to a network load. 'I'he importance of this application may bestbe realized by the central station operator who is now required to utilize a complicated relay arrangement for insuring the iiow o1' power to a network load. The applicability of the present invention to network systems will readily vbecome appa-rent from a study of the novel means of altering the characteristics of the proposed synchronizing arrange- -ment. y

Since Vthe present invention does not provide.

automatic synchronization in the accepted usage of the` term, but merely veries the condition of synchronization, the term synchro-verifier lwill be used in the following description.

The synchro-veriiier operates on the induction principle, similar to an induction disc wattmeter, and comprises two electro-magnet elements adapted to effect the rotation of suitable disc elements for actuating a set of contacts. The two` electro-magnet elements are positioned in vertical alignment and the two disc elements are adapted to rotate the same spindleror shaft and the contact means associated therewith.` The electro-magnet elements are of substantially the usual construction with an important exception,

the nature and purpose of which will be fully explained later. These elements embody the usual upper and lower pole portions, adapted for the reception of suitable flux producing windings, and the torque, resulting from the interaction of the pole fluxes of the respective electro-magnet elements, effects a resulting rotation or turning torque to actuate the single contact spindle.

The function of the synchro-verifier being to permit the connection of two independent systems or bus sections within predetermined limits of electrical conditions, it is necessary. to compare the respective voltages in some suitable manner.

For this purpose voltage transformers mayv be employed or the charging current of the condenser or oil-nlled bushings on the circuit breaker may be utilized, together' with any necessary phase-angle or power-factor correcting network. For present purposes, the application of the synchro-verifier will be described with reference to voltage-transformer energizing means.

The upper and lower electro-magnet elements will be referred to as element A and element B,

ment A is energized directly in accordance with the voltage on one side of the open circuit breaker while the lower coil winding of element B 'is energized in accordance with the voltage on the other side of the open breaker. The reference to the synchro-verifier in combination with a circuit breaker, throughout the specification, includes the application of the present invention for verifying the conditions of synchronization between two systems or busses connected to the respective terminals of any suitable circuit breaker.

The upper lcoil windings of elements A and B arev connected 'in parallel and energized in accordance with the dierence voltage between the two systems, and may be referred to as phasing windings. The lower coil winding, or voltage winding of element A, is adapted to 'produce an alternating-current flux which combinesfwith the flux produced bythe phasing winding of that element to eifect 'a rotating torquev acting upon-the associated disc element to rotate the contact spindle in an assumed positive direction. For the same two system voltages the voltage and phasing windings of element B are arranged toeffectV a rotating torque acting upon the disc element of element B in an opposedor negative direction. Thus, 'assuming the two systems to be in energized condition, the elements A and B exert opposing torques and the single contact spindle is rotated in accordance with the resultant torque developed by the two elements. The assumed positive direction is that of contact closing while the opposed or negative direction relates to a torque acting to open the contacts. i

Under most system conditions, the two electrical torques are opposed, that is, when one element is exerting a positive torque, the other element is exerting a negative torque. However, under some conditions this torque relation is not strictly true.

adjusted. The nature of the electrical torques which may be obtained in the synchro-veriiier will be treated in more detail hereafter.

In order to better understand a form of construction and the function and operation of the present invention, reference will be made to the several drawings wherein,

Figure l is a view, in front elevation, of a preferred embodiment of the present invention,

Fis. 2 is aview inside elevation, partly in section, taken on the line II-II of Fig. 1,

Fig. 3` is a schematic diagram illustrating the wiring connections of the synchro-verifier,

Fig. 4 is a vector diagram representing several possible voltage conditions with one adjustment of the synchro-veriiier,

Fig. 5 shows the general vector relation existing between the two system voltages as applied to the synchro-verifier,

Figs. 6 to l1, inclusive, are diagrams illustrating the vector relation between the respectivf4 voltages for diil'erent possible settings and characteristics oi the synchro-Vernier,

Fig. ,12 is a schematic wiring diagram of a simple application oi the present invention for verifying conditions of synchronization between twoenergized systems, and

F;g. 13 is a schematic wiring diagram of the4 `present invention comprises `a base portion 1 for housing the elements A and B oi the synchroveriiier. As stated hereinbefore, the mechanical structure ci the two elements is substantiallyv the same, the iron laminations and windings being assembled upon a movement frame 2 by means of screws or bolts 3 and the movement trame assembly fastened to raised portions 4 oi'the base portion 1 by means of screws 6. The elements A- and B are comprised of iron laminations 7 having upper poles 8, lower poles 9, phasing windings 11, voltage windings 12 and disc elements 13.

The iron laminations 7 are in two portions, the laminations comprising the upper poles 8 being dove-tailed with the laminations comprising the lower pole portions 9. In an ordinary electromagnetl element, such as provided in a Wattmeter. the lamnations comprising the upper and lower pole portions are secured firmly as a unit. .However, in the present invention, the lower pole laminations are secured together by machine screws 14, nuts 16 and washers 17, and the upper pole laminations are firmly secured by front plate members 18, rear plate members 19 and machine screws 21.

The movement frame 2 is shown partly in section at 22 (Fig. 2) in order to more clearly indicate the relation between the front plate members 18 and elliptical holes 23 in the movement frame. The front plate members 18 are provided with slots or holes 24 adapted for the reception of any suitable prying or moving means which may be inserted through the holesV 23 for the purpose of moving the upper pole laminations with respect to the lower pole laminations. The provision of this adjustable feature permits desired characteristics to be imparted to the syncroverifier, either atthe time of assembly in the factory or in the ileld application.

A spindle or shaft 26 is associated with the two disc members 13 by usual clamping means 27 and is adapted to rotate in a suitable lower bearing structure 28'. The upper bearing, not shown in the ligure, is of the pin type. It will be observed that the spindle 26 is so aligned with respect to the movement frame 2 that only small portions of the discs 13 rotate between the poles of the respective electro-magnet elements.

'Non-magnetic lag plates 29, such as copper, are provided for elements A and B and are adapted to lag the flux of the main pole or voltage windings 12. The lag plates are carried by L- shaped brackets 31 which may be secured to the movement frame 2 by means o! screws 32 and spring washers 33. The brackets 31.are provided with slots 34 for the reception of the screws 32 and the lag plate assemblies are adapted to be moved laterally with respect to the pole 9 by means of Vernier screws 36. Guide members 37,

integral with the movement frame 2, are provided for the reception of the screws 36. By turning the Vernier screws 36, the amount of flux lag and, therefore, the torque characteristics of either or both of the elements A andB. may be adjusted as desired. It is unnecessary toloosen the screws 32 in making this adjustment. Y

A permanent'magnet 38 is associated with the disc element 13 of the electro-magnet element A and provides a damping characteristic in the di rection of disc rotation. This magnet, as is usual in damping magnets, comprises two permanent magnets positioned in opposed polarity and clamped together by means of iront and back plate members 39 and countersunk screws 41. The back plate members 39 are adjustably positioned on the movement frame 2 by means of lslots 42 and holding screws 43.

The damping effect of the magnet` 38 may, therefore, be. modified by loosening the holding screws 43 and moving the magnet assembly laterally with respect to the disc v13.

A bearing bracket 44, of substantially U-shape, is secured to the upper portion4 of the movement frame 2 by screws 46 and supports a counteshaft 48 and gear 52. The countershait 48 is positioned 100 between the U arms of bracket 44 'by means of lower and upper bearing structures 49 and 51 respectively, and a gear 52 is associated therewith and meshes with the pinion 47 on the shaft 26. l

The counter-shaft 48 is covered with a moulded 105 insulation hub 53, around which the moving contact arm 54 is clamped by means o1 a screw 56. A suitablecontact, preferably silver, is secured tor the contact arm 54, as shown at 57. An L-shaped spring-adjusting bracket 58 is secured to the 110 bracket member 44, but removed therefrom by an insulation block 59, by means of screws 60. One of the screws 60 serves as a clamping means for `an electrical conductor 61. The spring acljusting bracket 58 is adapted to adjustably hold a spring adjusting hub and plate member 62 by means of screws 63 and lock washers 64. The member 62 is iitted around the insulation hub 53 and permits the free rotation of the hub and of the counter-shaft 48. A vertical portion 66 of plate 62 is secured to the outer end of a spiral spring 67, the inner end o! the spiral spring being secured to a projection of the contact arm 54, not shown.

Y An electrical connection is thus effected between ing block 69 by screws 70 and the block 69 is, in 135- turn, secured to the movement frame 2 by screws 72. One of the screws 70 is utilized to clamp an electrical conductor 71 and, when the contacts 57 and 68 are closed, an electrical connection is provided between 61 and '11. 1,40

When the spiral spring 67 is given an initial positive tension, the contacts 57 and 68 'are closed position, and the value of such tension may be changed as indicated above. If. the spiral `spring 67 is given an initial negative tension, the

contacts 57 and 68 are in open position and the tension in this direction may be modified at will.

A stop member 73 is secured to the disc element 13 of element B and permits approximately v195" 150 prevents injury of thesulators 84 and screws 86. Contact-screws 87 are provided for clamping the respective electrical conductors associatedwith the terminals,y Vand a grounding terminal 88 is secured to the base 1.

Stud members 91 are securedto raised portions 92 in the base 1 and are adapted to receive and hold in position a glass cover 93 by means of jcooperatingthumb'nuts 94. A gasket or washer 96-l of any suitable material, such as felt or cork,'is placed between the cover 93 and the base .1 and alords a dust-proof'and resilient connection.v f i Inforder to b'etter understand the functionof Vthe -synchro-verifier for the different 4possible lsynchronizer or relay characteristics; it Willbe'as-` sumedthat the voltage coil 12 of elementA is en ergized in accordance with one system voltage,-

the voltage coil 12 of element B is energized in accordance with the voltage of a second system, and the phasing coils 11, of both elements, yarev connected in parallel and energized in "accord-f.

ance with the difference voltage existing between the two systems.`

vFor ordina-rysynchronizing purposes, :the-

tcrques developed by elements A and B, under the same electrical energizing conditions, are made equal and opposed. Obviously, if the voltages of the two systems are equal, in phase and ofthe same frequency, the phasing coils 11 are not en ergized and there is no torque effected by either element unless the over-voltage adjusters or copper lag plates are moved toone side or the other. The provision of the over-voltage adjusters permits the imparting of any desired torque charac,- teristic to its associated element, the resultant ydi-f rection of such torque depending upon the direc` tion of movement of the lag plate. This torque results when only the voltage coil is energized, and an important application of the present inven-A tion is made possible by reason of this feature. This application relates to alternating-current network systems and will be considered in detail hereinafter. ,p

Another important adjustment is provided in the means for moving the upper pole laminations with respect to the lower pole laminations oi' each element. The torque developed by one ele' nient may thus be varied relative to the torque developed by the other element and this adjust-` ment permits the accurate balancing of thev torques of the two elements when both are ener-- gized under `the same electrical conditions. This," adjustment is usually made at the time of manufacture of the synchro-verifier, but obviously, in view of the adjustment described hereinbefore, the characteristics of the present invention may be altered as desired by the user in the field,

The potential coils 12 of elements A and B are so designed that the main pole flux lags the im-v pressed voltage by approximately and the phasing coils are so designed that the phasing coil fluxes are substantially in phase with the phasing coil voltages, with the result that each electro-magnet element haswatt characteristics` that is, zero torque is produced on either element when the voltage impressed across the phas-y ing circuit of that element leads or lags the voltage impressed across the voltage coil of that velement by 90. A schematic representation of means for lagging the pole flux eii'ected byI the contacts will be the following'` description of :the electrical characteristics of= the present invention', the electro-1 ,magnet elements of the synchro-verifier will be presumed to have substantiallywatt charactermics. f 1 y Y One object ofthe "present invention being to etl'ect the connectionlof two energized systems within .a p'redeterrxiined range of v'electrical conditions, reference will be made to the vector representation-of Fig.l 41 for purposes of explanation. 'All of the torquesacting to close or maintain the synchro-veriilercontacts closed will be considered pos-itive'and -all contact opening torques will be Vconsidered. negative. Assuming the re spectlve-torques'of the two elements to be equal and opposed under the same electrical energizing conditions,` and' no electrical torques produced when only the voltage coils are energized, an explanation of the principles upon which the synchro-verifier operates when the spiral spring is exerting a positive torque will be considered.

In-the vector'diagram 'of Fig. 4, E1 represents the voltage on one side of an open circuit breaker, Eirpresents the voltagev on the other side of the circuit 'breaker and E3 represents the voltage across the operi' circuit breaker or the difference between the voltages Ei and En. Assuming the voltage Ez to be equalto and in'phase with the voltage E1, the vdifference voltage E; is zero and the 'electrical torque developed will be zero for each'element, thereby resulting in the relay contacts-being closed vtx'cause of the'initial tension on the spiralcontrol spring.

Now-assuming the voltage E1 to remain constant and-that thevoltage Ez increases along the lineOD, an electrical torque will be produced and, with the 'voltage coils 'of the elements A and B energized in accordance with the voltages E1 and-E2, respectively, element A will produce a contact closing torque and element B will produce a contact opening torque.

In view o1' the'watt characteristics of `thevtwo vcosine of the angle between them, while the contact opening torque developed by element B will'be E: times E3 times the cosine of the angle between them. Thus it may be seen that the '.'contac't closing, orpositive, torque of element A is increasing as E3 increases, but the negative torque developed by element B is also increasing and at a faster rate' due'to the fact that not only is 'En increasing but E2 is increasing and the angle between En and Eris ybecoming smaller.

It follows, therefore, that the resultant elec- -tricaltorque isv becoming more and more negative vasthewoltage- E2 increases along the line vrOD until some point, such as point L, is reached. lit point L, the resultant negative electrical torque -just balances the positive v torque of the spiral control spring and for any further increase in E2 beyond the point L. ther resultant electrical ytorque developed will be greater than the torque developed by the spiral control spring and the positivelyheld open by a torque J equal toA the resultant 'electrical torque minus the torque of the spiral vcontrol spring. Next assume the voltage Ez to again be equal to and in phase with the voltage E1 and decreas- Y ing alongtheline-C. The torque developed by lelement lA'is now negative and increasing as Ex'inzcreases. 'I'he torque producedby element by an anglel of substantially 90, land the uxes crease as fast as'the negative torque produced v.by element A so that when a point, as point M, is reached, the 4resultant electrical torque .will

:lust equal the torque of the spiral control spring and anyfurther decrease .in the voltage E2, past the point M, 'effects a resulting negative electrical torque which is greater than the torque oi.'` the spiral control spring and provides a resul- I ant contact opening torque.

IIS

In a similarmanner, the` torque characteristics may be determined when the voltage E2 is Iincreasing along the line OF or decreasing along the line OG. Assuming. the voltage Ez to' be increasing along the line OF, the-element Aeilects .a positive torque which is increasing as Ea increases. At the same time element B is producing a negative torque,.fwhich increases as En and Ea-increase, and also because of the decrease in the angle between Egand Ea.v At a point N,

the resultant electrical t'orque and the torque ofthe spiral control spring are equal and the further increase oi the voltage En effects a resulting contact opening torque.' Conversely, when" the voltage E2 is decreasing along the line OG, the negative torque produced by element `A is increasing at a faster rate than the increase in positive torque produced by element B, with thef result that at a point P, the resultant electrical torque is equal to the torque developed by the spiral control spring. Further decrease of the voltage En eiectsa resultant contact opening torque.

' It may be shown that the torque balance points L, M, N, and P fall on the circumference of a circle having its center at O. Thus, for any given initial positive tension on the spiral control spring, the locus of all of the points at which the resultant electrical torque just balances the torque of the spiral control spring is a circle with its center at'O, labeled Operating curve. The following mathematical derivation of the Y relay'characteristics should aid in the understanding and application of the synchro-verifier or relay.

The several contact-closing torques may result either from the torque effected by the initial tension imparted to the spiral control spring, or by the torques produced by the electro-magnet elements A and B. The torques produced by the two elements A and B in turn result from thev usual torque developed by thevinteraction of the fluxes of the respective voltage and phasing windings or by adjustment of the copper lag plate or over-voltage adjuster associated withl each element.

Reference will be made to the vector diagram of Fig. 5, wherein any assumed relation may exist between the voltages Ei and E2. Again Ei is considered as the reference voltage and the voltage E2 is represented as leading the voltage E1 by an angle The angle between the voltage E1 and the phasing or difference voltage E3 is represented by the angle 0, and the angle between the voltage E2 and the .difference voltage E3, is represented by the angle qi. In other words, I

in the vector diagram of Fig. 5,' the voltage E3 leads the voltages E1 and Ez by the angles 0 and respectively. y

inasmuch as the respective fluxes produced by the voltages Ei and E2 lag the impressed voltages tive voltages Ei' and En will be assumedl to lag. by an angle of 90a.

Since the maximum torque is provided when the iluxes produced by the respective phasing and voltage windings are in phase, it follows that when the difference .voltage E: leads either the voltage E1 orEz by the angle a, the torque produced by the particular energized element will be at ;a maximum. The maximum torque line for element A is, therefore, indicated by line AA and leads thevoltage E1 bythe angle a. Similarly, the maximum torque line for element B is indicated by the line BB and leads the voltage En by the angle a.

Since the torque developed by the spiral control spring is independent ofthe electrical energizationl conditions of the'relay, the torque thus derived may be represented as a 'constant or T1=K1=torquedue to spiral control spring.

The torque of the spiral control spring is considered to be in a contact-closing' direction and is therefore made positive. From the above con-v sideration oi the torques developed by the elements A 'and B, the respective torque equations may be written, and for the conditions represented by the vector diagram, the torque developed by element A is positive and the torque developed by element B is negative.

Tz=KzE1Ea cos (-a=torque produced by the voltage and phasing coils of element A.

Ta: -KzEzEa cos (o-.a :torque produced by the v. voltage and phasing coils of element B. i

T4=K3E12=torque from overvoltage adjuster of element A.

T5=K4E=torque from overvoltage adjuster of element B.

'I-'he two torques T4 and T5 are obtained by assuming that the overvoltage adjusters of elements A and B are so positioned that a definite amount of :torque is produced when only the respective voltage coils are energized, and the constants Ka .andf'Ki are made different, assuming that the adjustments are different on the two elements.

The'total torque developed by the synchro-- verifier or relay is equal to the algebraic sum of all of the respective torques, or

To obtain the operating curve,.the total torque, To, must be equal to zero, or

K3E12+K4E22=0 (1) sin a (sin 6 ccs -cos 0 sin (2) From Fig. 5,

I Eri-E3 CO8 6 COS -T and' E3 sinsv Substituting the above valuesfor cos and sin ln Eq. (2) 1 In Eq. (7) if K3=K4=0 M=K2 cos e: End N =O Therefore, when no torque is produced by either yelement when only the voltage coils are energized. the value of the diii'erence or phasing voltage Es becomes,

This equation shows that E; is a constant when K1 and K4 are zero, and vtherefore that the locus W01. i Z sin o; [(W) E; sin @cos 0 1 (rf E. )l E. (E1 cos 0 cos a-i-Ea cosi @cos +En sincosa-f-Eisinasina-l-Essino cossin a-Ez sln-cososin u) substituting `um vame of cos f-a). from Eq. (4i in Earn, s y

As mentioned vhereinbeiore.' the electrical torques developed by elements A and B are usually 'opposedvandq it is only under certain phaseangle relations between the diil'erence voltage' and the potential coil voltages of the respectivev It will be seen from'Eq. (5) that Eq. (1). has been simplied by eliminating the term.V In orderto simplify Eq. (5) it is possible to eliminate theEz term by substituting the 'equivalent therefor in terms o! E1, E: and cos 0.'

Since,

.- Let and'iet uns, NK, cos a-x.

elements, or when phasing voltage is. zero and the 'ov'ervoltageI adjusters are ineffective, that the respective torques are not opposed.

Fig. 6 is illustrative of the general relationbetween the potential coil voltages of the elements A and B and the phasing voltage for diilerent adjustments of the spiral control spring and with lthe overvoltage adjusters of each element positioned for aero torque from the potential coils alone; The reference voltage is again assumed to be E1 and thedifi'erence voltage E: is shown leading E1. 'Ihe operating circles 101, 102, 103, 104 and 108 are obtained by changing the tension onthe spiral control spring, the torque delivered thereby being in a positive or contact-closing direction. In view of the characteristics of the present invention, as evidenced by the above mathematical derivation, the yeilective value of the diiIerence voltage E: is a function oi' the initial torque .imparted to the spiral control spring; Obviously, the diameters of radii of all of the possible operating circles also vary in 4accordance with the initial tension -of the spring;

the smaller the` operating circle the smaller the spring torque.

With the vector relation of the voltages E1 and Ez, as shown, the lcontacts of the relay will be maintained in open position when the spiral control spring is adjusted for either of the operating circles 101 or 102, and the contacts would be held closed when the spiral control spring is adjusted to provide operating circles 103, 104 or 106.

Referring to Fig. 6 again, and assumingthe relay to be adjusted for operating circle 103 and the voltages E1 and E1 to be as shown, a definite amount of time is required for the relay contacts to be closed,l dependingupon `the respective torques and the damping effect provided by tbe permanent magnet. Obviously, the amount of time required for the relay contacts to close, under`. energized conditions, may be varied by adjusting the position ofthe damping magnet and bymovlngboth of the upper pole structures of the ,two electro-magnetelements.v Assuming any definite time required for the contacts to be closed after the phasing or difference voltage Ea falls within the operating circle 103, it is obvious 1 that this time determines the beat frequency which mayexist between the voltages E1 and En, and still permit the closing of the relay contacts. In other words, assuming a beat frequency to exist between the voltages E1 and E2, the time required 4for the -relay to close its contacts after the phasing or difference voltage falls within the operating circle 103 must be less than the time required for the voltage Ez to move through the operating circle 103 in order for the relay contacts vto close.- This will later.

be explainedin more detail From the above, it may be seen that by changing the characteristics of the relay to effect the closing of the contacts within any predetermined time, the permissible beat frequency between the two voltages may be varied at will. "It is quite obvious that the contacts separation maybe changed to effect different time intervals of operation of the relay. and the stationary contact is therefore made adjustable.

Assumingthat E2 is equal to E1. is in phase lwitl'li, and is of the same frequency so that the two vectors shown for Ez and E1 coincide, under this condition, the synchro-verifier will close its contacts after a predetermined time from the extreme' open position, when operating circle 103 is being used. Assuming the required time to be flve seconds, it is obvious that sincel no electrical torque is produced', the rclosing torque developed by the spiral control spring is effective inclosing vsu the contacts at the greatest possible speed. Under the same electrical conditions, the contacts would close at a much slower rate if operating circle 101 was being used, dueto the decrease in the amount of spring tension.

Assume the electrical conditions to be the same with the exception that thev two voltages are of different frequencies, so that E; slowly moves through the operating circle 103 at a uniform rate of speed, and that approximately five seconds are required for it to move from 15 lagging to 15 leading with respect to E1. Underl this condition' the contacts will not close if operating circle -103 is being used since zero resultant torque is produced when E2 is 15 lagging andA maximum resultant torque is produced when E: is in phase with E1. As assumed above, five seconds is required for the contacts to close when thetwo voltages are in phase, so it obviously follows that a longer time is required for the contacts to close when the two voltages are of lEl.

'beatfrequency is obtainedby assuming theoperating circle 103 to limit the effective rotation of En from 15 lagging to 15 leading with respect- From the foregoing, it is clear that corresponding smaller beat frequencies are required for the contacts to close if operating circles with smaller diameters than 103 are being used. `It is furv'ther apparent that for any given diameter of operating circle being used, .the permissible beat frequency is changed when the magnitudes of the two voltages Ez and E1 Aare changed.

VIn Fig. 7 the relay characteristics are such that operating circle 107 is obtained by adjusting the initial tension of the spiral control spring and withv a zero overvoltage adjustment on both electro-magnet elements. The synchro-verifier contacts will be closed, providing the voltage vector E2 remains within operating circle 107 for a sufficient time, and it is clear that only a small phase-angle difference is permissible. Assuming 5 the Avoltage E1 lto be reduced in magnitude as indicated by the vector E1, the operating circle remains the same since the diameter thereof-is determined solely by the spring tension. With such reduced voltage condition, it is clear that a larger phase-angle difference may exist between the reduced voltage E2 and the reference voltage The operating circle 107 is of the same diameterfas operating circle 107 and, irrespective of the voltage magnitudes, for any predetermined spring settir diameter of the relay operating circle remains constant. y In Figs. 6 and 7 the ysynchro-verifier is provided with a zero overvoltage adjustment and in this case the constants K3 and K4 are zero and Eq. (8) applies. L

Referring to adjusted to produce'an initialnegative torque and the relaycontacts are maintained in open position when the two electro-magnet elements are deenergized. The overvoltage vadjuster of each element is adjusted to produce`a positive or contact closing torque and it may be noted that the center of the resulting operatingcircle 108 does not coincide with the end of the E1 voltage vector, and furthenrthat when the voltage Ei is reduced to a value as indicated by the'.

vector E1', thel diameter of the operating circle is rlrgterially reduced; as shaw-n by operating curve Assuming the overvoltage adjustment on element B is made zero so that the N term in Eq. (7) drops out, and that the overvoltage adjustment of element A is made positive, the mathematical expression indicates that the center of the operating circle should coincide with the end of the voltage vector E1, and that the diameterv of the operating circle is determined as a function of the spring tension and the square of the potential coil voltage of element A. However, with relay characteristics vcorresponding to the Fig. 8 representation, both of the elements A and B are provided with an overvoltage adjustment .and the diameter of operating circle 108 is de- Fig. 8. the spira'hcontrol spring is ing circle is materially reduced andv the relay made more sensitive.

It is of interest to note that with the relay ad- ,justed for the characteristics shown in Fig. 7, the

sensitivity is decreased with decrease inl voltage,

-while, the relay' ismore sensitive for reduced voltage conditions when adjusted for the characteristics shown in Fig. 8. 1

Fig. 9 represents the relay characteristics when a negative spring tension is 'utilized and the balance is destroyed 'between the two electro-magnet elements bythe adjustment of only the overvolt- 1age adjuster of element Ato effect a positive torque. As referred to hereinbefore, this adjustment of the relay should provide that thefcenters of the operating circles coincide with the-end of the voltage-vector E1. 4It'will be observed, however, that according 'to Fig. 9 the centers of the operating circles do not coincide with the end of vector E1. The apparent contradiction is dueto the action of the overvoltage adjuster in actingv tween elements A and B is disturbed and the formulas derived in the mathematical analysis will not apply. The operating curve 111 is shown with its center slightly removed from the end of vector E1, and the operating circle 112 is obtained byl an increased movement of the overvoltage adjuster, with the result that the center thereof is substantially removed from the end of vector E1.' The operating'circles 113 and 114 correspond tothe relay characteristics as adjusted for operating circles 111 and 112, respectively, when the voltage lE1 is reduced to the value shown by voltage vect'or E1'. v

Ihe centers of the operating circles may be made-to coincide with the end of voltage'vector E1 were the same kind of operating torque, as provided bythe overvoltage adjuster, introduced by a means whch would not affect the impedance of the phasing circuit. Obviously this means could be in the form of athird element which x would produce a'. torque proportional to E1. I'his third element could be associated with one of the disc members and a fourth element, for introducing a torque proportional to E22, could also be provided and either be associated with one of the disc members, or the third and fourth members could cooperate with a third disc member to' effect any desired torque proportional to E12, E22,

- or both.

,In the above explanation of the relay characteristics, as shown in Fig. 9, the operating circles having their centersremoved from the end of voltage vector E1 were obtained by changing the impedance and power factor angle of the phasing coil magnetic circuit of element A. It follows, therefore, thatv any desired relay characteristicsmay be obtained by altering the impedance and power factor angle of either phasing coil 'y magnetic circuit, or both.

element B is shunted by areiatively largey relsistance. The radii of all of the respective operating curves shown in Fig. 10 indicate the position of.

the centers of the operating curves relative to the end of voltage vector 'En Curve 117 may be obtained by shunting the phasing coil of element B with a smaller resistanceand operating curve 118 may be obtained by shunting the phasing coil of element B with an equivalent impedance.

Operating curve 119 may be obtained by shunting the phasing coil of element A with an equivalent impedance and curves 121 and 122 may be obtained bylshunting the phasing coils of elements A and B, respectively, bya small capacitance.

VThe various operating curves illustrated in this figure have been indicated in a purely arbitrary manner and it is to be understood that by altering the type and magnitude of the shunting `means, the position of the respective centers and the length of the radii may be modified at will.

In this respect an operating circle, similar to operating curve 123 in Fig. l1, may be obtained with the result that the relay contacts will'not be permitted to close until the voltage vector Ez falls within this curve and remains there for a predetermined time. Such relay characteristic is particularly advantageous in the application of the relay to network distribution systems, wherein it is desirable to permit the closing of a network switch or circuit interrupter only when the current which fiows after the switch is closed, is in a direction to insure power fiow from a feeder circuit to a network load.

Assuming the potential coil of element A energized in accordance with the network voltage, thev potential coil of element B energized in accordance with the feeder voltage and the respective vThe operating curve 123 is confined to substantially the 'leading quadrant, considering the voltage vectorEi as the reference voltage, and it is necessary for the feeder voltage E1 to terminatev within this circle and remain there for the necessary predetermined time for the relay contacts to be actuated to closed position. l

By confining the range within which the phasing voltage may fall to substantially the leading quadrant with respect to the network voltage E1, the relay effects the closing of the network switch, and the current which flows as a result of this phasing voltage will not lag sufficiently to cause power to flow from the network to the feeder. In other words, since a usual directional relay is provided for effecting the automatic opening ofthe network switch, such relay would not be effectively energized to immediately 'open the network switch 'when the switch is closed and the phasing voltage leads the network voltage.

Assuming any phasing voltage to exist across the break-, contactsof the network switch, theoretically `the resulting current flow would lag this voltage by an angle of when the network load is purely inductive. In practice, however, this 4angle of lag usually falls within a range of between 20 and '70 andso it is inadvisable to permit the effectiveI phasing voltage to lag the network voltage-by an angle greater than 20. Since the closing range should be limited as above stated, the

, for the application o! the related Within a the respective. disc amarsi-,- relay jo! the' present invention,f provided with 11 adJustme'nt,

characteristics similar to the Fia.

may be usedA very advantageously in network sys- Vtems ior effcctingthe proper closing oi' a network Switch.

' VThe application ci the present invention network, systems oilersa iurtheradvantage in that mined with a zero adjustment of the over-voltage adjusters while the' remaining figures are illustrative oi' different possible adjustments of the overvoltage adiusters, or the equivalentthereoi'.

Fig'. 12 is a schematic wiring diagram o! a usual application of the the condition of'synchronism between two energized systems. One system 126 is represented as a long transmission system or section of a loop or ring system and is adapted to be energized from a bus or feeder circuit 127 through circuit breaker 128. The system 126 and bus 127 are shown as three-phase circuits, vonly for purpose of explanation, and it is obvious that any alternating-cur rentcircuits may be understood as being proper present synchronizing arrangement.

A second system 129 is also represented as any proper alternating-current circuit and is adapted to :be energized from any suitable source, as 4bus 131, through circuitbreaker132.

Assuming that thetwo circuits 126 and 127 are adjacent sections ci' a loop system and that a connecting circuit breaker 133 .hasbeen actuated to its open position, as shown in the drawings, this breaker should not be closed unless the characteristics of the two circuit voltages are lpredetermined range of electrical conditions.

For this purpose the synchro-verifier is provided and is indicated schematically as comprising the two electro-'magnet elements A and B,

47 .and 53, spiral control spring 67, moving contact 54 and stationary contact means 68. The phasing and voltage windings of the elements r VA and B are indicated by 11 and 12, respectively.

and the upper pole laminations 8 oi' both elements A and B are properly positioned with respect to the lower pole laminations 9, so that equal and opposite torques are produced when the two elements are energized under the same electrical conditions. In this application of the present invention, the overvoltage adjusters (not shown) are adjusted for zero torque condition and the relay operates in accordance with the characteristics shown in Figs. 6v and 7. Thediameter of the desired operating curve is de termined solely by the initial positive tension imparted to the spiral 4control spring 67 and, theretore, under deenergized conditions the relay ccnvtacts 68 are bridged by the moving contact 54.

A voltage transformer 134 is electrically connected across one phase of the circuit -126 and a, second voltage transformer 136 is electrically connected across the corresponding phase o1' the circuit 129. One terminal or the secondary transformer 136 by' means is groundedat 138. The nal oi' transformer 134 o! the breaker 133,

present invention for verifyingv .through a resistor 147. The is, therefore, energized in 1-1 for the protection thereof elements 13, spindle 26, gearsv l 9 winding .of transformer l134 is connected to the secondary. terminal of corresponding polarity or ot conductor 137. and other secondary termiis connected to one terminai connection of the voltage winding 12 of element A by conductor 139` through contacts 141 and pallet switch 142 associated with vthe breaker 133. The other terminal connection of the voltage winding 12 is connected to the conductor 137 to thereby eiect the energization of the winding 12in accordancwith the secondary voltage of transformer 134.

'Ihe remaining secondary terminal connection of. transformer 136 is connected to one terminal connection or the voltage winding 12 of element B through contacts 143 and pallet. switch 144 and conductor 146. The remaining terminal oi' the voltage winding 12 is connected to the conductor 137. thereby com pleting the energization thereof in accordance with the voltage of breaker 133 is in open position. 1 l

The phasing winding 11 of element A hasone Ate vconnected to the conductor 139 while the other terminal is connected to conductor 146 accordance with the diiierence or phasing voltage between the systems 126 and 129. l The resistor- 147 is provided for the protection or the winding 11 inthe event of the two system voltages being 180 out of phase, in which be twice normal,

The phasing winding 11 of element B is connected-to `the with the phasing winding 11 of element A. and a resistor 148 is provided in series with winding under the above mentioned out-of-phase condition.

.One of the relay contacts 68 is connected to conductor 139 and the other contact 68 is connected to the energizing winding 149. oi' an induction typefrelay 151, the circuit is lcompleted from to the conductor gized in accordance with the the winding 149 voltage across the tacts of the synchro-verifier;

The voltage relay 151 is shown schematically as comprising a c-magnet 153 having a shading coil 154 and a disc armature'156 adapted to be rotated in accordance with the energization o1' winding 149, a spindle 157 adapted to be rotated by the disc 156, a contact 158 carried by said spindle contacts 159 adapted to be closed 4 The rotation oi' the armature 156 is damped by a permanent magnet 161, and with the winding 149 deenergized, a spiral spring 162 serves to maintain the contact 158 out of engagement with the stationary contacts 159.

one or the contacts 159 is connected to one line of any suitable 163 and the other contact 159 is connected to the other line of the bus 163 through the closing coil 164 of the circuit breaker133. Contacts 166 are associated with the breaker V133 and are adapted to be bridged by pallet switch 142 to buttcn 167` .dicated generically as a normally closed push phasing winding 11 through resistor 152, and

137. The winding 149 is ener--v direct current sourceor bus circuit 129 when the circuit.

conductors 139 and 146. in parallel Assuming only the circuit 126 to be energized and, therefore, the circuit breaker `133 to be in open position, thev voltage coil 12 of element A is energized by the full secondary voltage of potential transformer 134 and the phasing coils'll of elements A and B are energized in parallel,v

the parallel phasing coilsbeing connected in series with a parallel circuit comprised of the voltage coil 12 of'element B and the secondary winding of the potential transformer 136. Consequently, a strong torque is produced in the contact opening direction. Similarly, if only the circuit 129 vis energized, the coils 11 and 12 willA be energized in like manner, except that voltage coil 12 of element B will have full voltage impressed across it,

and a negative or contact-opening torque will be produced. 1i' both circuits 126 and 129 are deenergized, the contacts 68 would be bridged by the arm 54due to the action oi' the spring 67. II the contacts 68 were connected directly toA the breaker closing coil 164, the circuit breaker 133 would be closed as soon as either circuit 126 or circuit 129 were energized. Although a contactj opening torque would be produced upon the energization of either circuits 126 or'129, the contacts 68,'being initially closed by the arm 54, would not be opened quickly enouglrto prevent closure oi.' circuit breaker 133.

- tends to injure the breaker. is used, the contacts 68 will be opened before the To show the undesirability of such operation..

contacts 159 are closed. Thus the coil 149 of the relay 151 will be deenergized and the contact arm 158 will reset.

The connections of Figure 12 therefore should not beused except where provision is made for energizing the two separated circuits, such as circuits 126 and 129 at their opposite ends. When the circuits are thus energized, the synchro-verilier connected as in Figure '12, will operate to connect the 'two circuits, as through breaker 133,

if the two voltages have the correct relations. The synchro-veriiier can be used, in conjunction with other relay means, for connecting the distant ends of circuits 126 and 129 to sources of energy,

and such an application will be described later. The requirements of such an application include the closure of the circuit breaker between th source and circuit when one or both are deenergized, and it has been shown that the connections of Figure 12 are not suitable for this.

In accordance with the above-mentioned application of the present invention and assuming both circuits 126 and 129 to be energized, the circuit breaker 133 is actuated to its closed position upon the bridging of contacts 159 by the contact arm 158 of relay 151. If the voltages, frequencies and phase displacement oi.' the circuits 126 and 129 are such that the adjustments of the synchroveriflers permit the contacts 68 to be closed, the winding 149 of relay 151 will be energized in accordance with the secondary voltage of trans former 134 and the contacts 159 are bridged .only after a predetermined time depending upon the amount of damping provided by the magnet 1.61,

the restraining action' of the spring 162 and the amount of separation between the contact 158 and contacts 159t The bridging o! contacts 159 completes the energizing circuit ior the closing winding 164 from the directfcurrent source 163 and the circuit breaker 133 is actuated toits closed position, the winding 164 being continuously energized by means of the holding circuit through contacts 166 and pallet switch 142. 'I'he section 129 is, therefore, connected to the section 126 and the circuit breaker 1,33 remains closed until some circuit breaker opening means, as push button 167 in the holding circuit for winding 164 is actuated upon the occurrence of any predetermined electrical conditions or at the will oi the station operator.

Next assuming they circuit breaker 133 to be at the'other end of the section 1,29, 'and the section 126 to be adjacent thereto, the breaker 133 will not be closed until the voltages oi.' sections 126 and 1 29 bear the proper relation required by the particular characteristics for which the synchroverier is adjusted. Assuming the two circuit z ation of the circuit for winding 149 o! relay 151.

As pointed out hereinbefore a definite amount oi' time is required in e'ecting the closing of the synchro-verifier contacts for any given relation between the two circuit voltages, and since the permissible beat frequency is regulated by this time lag, the provision of theV voltage relay 151 results in an appreciable lowering of the permissible beat frequency and the synchronizing arrangement is thus made more sensitive.

The provision of the voltage relay 151 is recomf mended whenever the synchro-verifier is adjusted for the characteristics shown in Figs. 6 and 7. This application oi! the additional relay 151 is quite obvious since the synchro-verifier contacts are normally closed and improper closing of the asiciated circuit breaker is therefore made poss e.

In some synchronizing applications, it may be desirable to increase the sensitivity o1.' the synchro-veritier when the magnitudes of the two system voltages are decreased or the provision of the additional relay 151 may be objectionable from the customers standpoint. In this case, the synchro-Vernier may be adjusted for the characteristics shown in Fig. 8.

Assuming the synchro-Vernier to be adjusted for characteristics as shown in Fig. 8 and the contacts 68 to directly control the energizing circuit of the winding 164, the relay 151 may be eliminated from the synchronizing arrangement. With the synchro-Vernier so adjusted, the contact 54 is normally held out of engagement with contact 68 by a negative or contact opening torque produced by the spiral control spring 67, and the overvoltage adjusters of velements A and B are adjusted for the desired operating curve.

ISO

ist

Obviously this simple arrangement may be use d y vapplications warrant and require the adjustment oi the'synchro-veriier for characteristics similar 'tics shown in Fig. 11.

speot, one application will be considered when the synchro-veriner is adjusted for the characterisii Referring to 12 again, assume the threephase circuit 129 to be energized from the second--r ary of a distribution transformer (not shown) and the feeder 131 to be energized from a central station -and supplying power through circuit breaker 133 to the primary of the said transformer. Next consider the three-phase circuit 126 to be connected to a network load (not shown) and regard the bus or feeder 127 as an additional feeder supplying power to the network load from a different source. 'I'he circuit breaker 133 now constitutes a so-called network switch and proper relay apparatus must be associated therewith for effecting the automatic actuation thereof under predetermined electrical conditions.

Assuming the network load to be energized by' means of the feeder circuit 127 and that it is desired to connect the additional feeder 131 thereto. the circuit breaker 132 is actuated to its closed position by the central station operator, in any suitable manner. Both the feeder circuit 129 and the network. load circuit 126 are now energized and the synchro-verifier is, therefore, energized in accordance with the voltages of thel two cir-y cuits. In this application it is to be remembered that the contact arm 54 is normally held out of engagement with contacts 68 by reason of the negative torque produced by the spiral control spring 67 and further, that the contacts 68 are connected directly in the energizing circuit for the circuit breaker closing winding 164. t

As required by the relay characteristics shown in Fig. 11, the feeder voltage which is attained after it closes, lagsthe voltage across the break contacts of the network switch'by an angle of from 20 to 70. It follows, therefore, that the4 closing range or operating curve may fall in the lagging quadrant withrespect to the network voltage, providing the maximum permissible lag of the phasing voltage does not exceed 20, and the current which flows as a result of such phasing voltage will never lag the network voltage by an angle greater than In this manner, assuming a directional relay to be provided for effecting the opening of the network switch upon the occurrence of power flow from the network to the feeder, the network switch is not permitted to be closed. unless the resulting current iiow is from the feeder to the network load, thus insuring proper power now to the network load and preventing the repeated opening and closing or viously, any directional relay for effecting the opening o f the network switch 133 upon the occurrence of a flow of power from the network `128 to the feeder 129, may be associated with a switch` such as push button 167 for de-energizing the holding circuit of winding,164.

A more general application of the present in'- vention is shown in Fig. 13 of the drawings and includes a relay arrangement associated with the synchro-verifier for insuring the closure of a circuit breakerassociated -witlr two systems under vany predetermined energized or deenergized sys- 'v tem conditions.

Referring to the drawings, a bus 171 is adapted to be energized from any suitable power source (not shown) through feeder 172 and circuit breaker 173. An incoming line or load section 174 is adapted to be energized from any suitable source (not shown) through feeder 176 and cir cuit breaker 177. The purpose of the present invention is to effect the automatic closing of a ycomprising elements A and B, the respective phasing and voltage windings being indicated by 11 and 12, respectively. Disc elements 13 cooperate with elements A and B to effect the rotay tion of spindle 26, and moving contact 54 is associated therewith through Vgears 47 and 52 and is adapted to bridge stationary contacts 68. The spiral control spring 67 is also shown and is adjusted for an initial positive or. contact closing torque.

One secondary terminal of transformer 181 is connected to the secondary terminal of opposed polarity of transformer 182 by conductor 183, and

the conductor 183 is grounded at 184. The other secondary terminal of transformer 181 is connected to one terminal of the voltage winding 12 of element A by means of conductor 188 through contacts 187 and pallet switch 188 of the breaker 178. The energizing circuit for this winding 12 is completed by connecting its other terminal to conductor 183, thereby resulting in the energizationof winding 12 of element A in accordance with the secondary voltage of transformer 181 when the circuit breaker 178 is in open position.

The remaining secondary terminal of transformer 182 is connected to one terminal of winding 12 of element B by conductor 189 through contacts 191 and pallet switch 192 associated with the breaker 178. The remaining terminal of the winding 12 is connected to conductor 183 to thereby effect the energization thereof in accordance with the secondary voltage of transformer 182 when breaker 178 is in open position.

One terminal of each phasing winding 11 of elements A and B is connected to conductor 186 and the remaining terminals are connected to conductor 189 through resistance elements 193 and 194, respectively. The phasing windings 11 are thus connected in parallel and energized in accordance with the difference voltage between the two systems 171 and 174. The resistance elements 193 and 194 are provided for protecting the phasing windings 11 when the two system voltages are substantially out of phase.

One of the stationary contacts 88 is connected to conductor 186 and the other'contact 68 is con nected to one terminal of the energizing winding 196 of an induction disc type voltage relay 197, the remaining terminal of winding 196 being connected to conductor 183 through a resistance 198. The relay 197 is shown schematically as com- Aprisingaai c-mag'net199` and a short-circuited 'turn 201, disc element-202rsplndle 203, reitrainf ing spring 204, moving contact 205, stationary contacts 206 and damping magnet 207.4 It may be noted'that the energizing windingV 196 is energized in' accordance with the secondary voltage of` transformer 181 when the synchro-verifier contacts 68 are bridgedby contact 54 and the resistance 198 is employed i'or .the protection of the synchro-Vernier contacts.' Avsecond voltage relay 208, substantially similar to relay 197, has one terminal oi.' its energizfng winding 209 connected in series with resistance 211 and thence to conductor 183 and the other terminal connected to conductor 186. vThe schematic representation of relay 208 comprises a C-magnet 212, short-circuited turn 213, disc element 214, spindle 216, restraining spring 217, moving contact 218, stationary contacts 219 and 221, and damping magnet 222.

The energizing winding 209 of relay 208 is also energized in accordance with the secondary voltage of transformer 181. -The contacts 219 are bridged by moving contact 218 under de- '.25'.

energized conditions of the relay 208 and the stationary contacts 221 are only bridged by contact 218 when the relay 208 is energized.

A thirdvoltage relay 223, substantially similar ,to relays 197 and 208, is represented schematically as comprising a C-magnet 224, main energizing winding 226, auxiliary winding 227, disc element 228, spindle 229, restraining spring 231, moving contact 232, stationary contacts 233 and 234, and damping magnet 236. One terminal of the 1 energizing winding 226 is connected to conductor 189 through resistance 237 and the otherterminal is connected to conductor 183. Thus, under deenergized conditions o! the relay, the contacts 233 are bridged by moving contact 232. vUnder renergized conditions of the relay, or'when thev winding 226 is energized in accordance with the secondary voltage of-transrormer 182, the stationary contacts 234 are bridged by moving contact 232.

type, is` ada ted to be energized from a separate alternating current source or from the voltage source orwteeder 172."V A motor element 239 is adaptedto drive a druin'241-having a contact member'242 thereon adapted for the bridging of stationary contacts 243. 'In the relay arrangement shown in -this drawing, the voltage source for relay 4238 will be assumed to be the power source lor feeder 172.

The. operation of the arrangement 'shown in Fig. 13 for the di'erent energized conditions of systems 171 and 174, is as follows:

Assuming the circuit breakers 173 and 177 to be in open position, thereby disconnecting the feeders 172 and 176 trom the bus 171 and section 174, respectively, it may be desired to close the circuit breaker 178 and connect the two circuits 171 and 174 before either circuit ,is energized. This closure of circuit breaker 178 is eccted by energizing the relay 238 and bridging the stationary contacts 243 by the contact member 242.

A circuit is thereby completed from the bus ci a direct current source l244 through the normally bridged contacts 233 of relay 223, contacts 243 and contact member 242 of relay 238, energizing winding 246 of a voltage relay 247, resistance 243 and thence to the positive bus of the direct current source 244.

The energization of the winding 246 of relay 247 effects the actuation oi.' said relay to close contacte'249 bygmeans oipallet'switch 251 and thereby complete -an energizing circuit for the closing coil 252 of circuitbreaker 178. This energizing circuit may be traced from the positive bus or source 244, through the' closing winding 252, contacts 249 'and Dalletswitch 251 ot relay 4247, vand thence to the negative bus oi source 244..- The actuation of the relay 247 also effects the bridging of contacts 253 Aby pallet switch 254 to complete a holding circuit for the energizing winding 246. This holding circuit may be traced from the positive bus or source 244, through the resistance 248 and winding 246. contacts 253 and pallet switch 254 of relay 246, and thence to the negative bus of source 244.

From the foregoing explanation, it is clear 'that the circuit breaker 178 may be actuated tu its closed position, even though circuits 171 and 174 are de-energized. l

Next assume that circuit 171 is energized from feeder 172 through circuit breaker 173. Trans. former 181 is now energized and the voltage wind.V ing 12 oi' element A is energized in accordance with the transformer secondary voltage. 'I'he phasing coils 11 of elements A and B are energized in parallel and the two paralleled phasing coils are connected in 'series with a second parallelcircuit comprised of .the secondary or the potential transformer 182, the voltage winding'105 l2 of element B andthe winding 226 of relay 223.

Since the impedance of the phasing windings 11 is relatively high, the winding 226 will not be sufficiently energized to actuate the relay 223, and the moving contact. v232 will remain closed against the stationary contact 233. The synchroveriiler will have a negative or contact-opening torque, so that the contact 54 will move away from the stationary contacts 68.

The energizing winding 209 of relay 208-is also energizedl in accordance with the secondary voit-` age or transformer181 and the moving contact 218 is actuated to bridge contacts 221. Since the circuit 174 and the transformer 182 are de-energized, the relay 223 is de-energized and the conw tacts 233 are normally bridged by the moving conf tact 232 as a result of the torque exerted by the restraining spring 231. j From an examination of the electrical connections between the contacts ot-relays 197 and 125 208, it will be seen that no electrical circuit is completed inasmuch as onev of the contacts 206 of relay 197 is connected to one of the open contacts 219 or relay 208 and also to one of the open contacts 234 of the de-eneigizcd relay 223, the 13g other contact 206 of relay 197 is connected to one oi the closed contacts 221 of relay 208, the other contact 221 being connected to the positive bus of source 244 through the energizing winding 246 of relay 247, and resistance 248. However, this' circuit is not completed to the negative bus of source 244 since the contacts 219 and 234 oi.' relays 208 and 223, respectively,'are not closed. From the ab0ve it becomes clear that in order to close the circuit' breaker 178 when the bus or j circuit 171 is energized and the circuit 174 is deenergized, the relay `238 .must be energized, as explained hcrcinbeiore, with reference to the clos ing ci circuit breaker 1781 whenboth of the cir cuits 171 and 174 are cle-energized, with the w sult that the closing coil 252 of circuit breaker 178 is energized, the circuit being completed through the normally closed contacts 233'01 relay 223. l j

Now assume the feeder circuit breaker 173 to 150 :,ovasss be open and thebug or circuit 171 cle-energized, andthefceder 176tobesiipi 1yinsp0wertothe circuit 174 through circuit breaker 177. Under these the synchro-verifier is energized as in the previous case' except that the voltage coil 12 of element B is now energized by the full secondary voltage ofthe transformer 182 and the voltagecoil 12 of-element A is energized at a much lower voltage since it is connected in series with the phasing windings 11'. The windings 196 and 209 of the respective relays 197 and 208 are also substantially de-energized, the contacts 206 of relay 197 being open and the contacts 219 of relay 208 being bridged-by contact 218.

However, the transformer 182 is-now energized and the winding 22,6 of1relay223 is energized `Vin accordance with the secondary voltage of transformer 182, withthe result that the moving contact 232 is actuated to bridge contacts 234. An energizing circuit for the winding 246 of relay 247 is thus completed from the negative bus of source 244, contacts 234 and 232 of the relay 223. contacts 219 and 218 df the relay 208, through winding 246 ofl relay 247, resistance 248, vpush button switch 256 and thence to the positive bus ofsource 244. ,A

The energizing circuit for the closing winding 252 of the circuit breaker 178 is effected by the actuation of the relay 247, as explained hereinbefore, and the circuit breaker isactuated to its closed position to connect the circuits 171 and 174. The winding 252 is continuously energized by virtue of the holding circuit fr relay 247, the nature of which has been previously explained.

. Now consider the bus or circuit 171 to be energized from the feeder 172 through circuit breaker 173, and the load section or circuit 174 to be energized from the feeder 176 through circuit breaker 177. The feeder circuits 172 and 176 y are presumed to be energized from different sources with the possible result that the voltages of circuits 171 and 174 are dissimilar and the twoV circuits arenotinsynchronism Under such energized conditions, and considering the circuit breaker 17a to be in open position, the synchro-verifier is effectively energized to maintain the contacts 68 closed or to open contacts 68 by rotating the moving contact 54.

The voltage windings 12 of elements A and B are now energized in accordance with the secondary voltages of energized transformers v181 and 182, respectively, and the phasing windings of both elements are energized in accordance with the difference voltage existing between the two secondaries of transformers 181 and the 182.V

The winding 209 of relay 208 is energized in accordance with the secondary voltage of transformer 181 and the contacts 221 are bridged by contact 218. The winding1226 of relay 2231s enof the circuit breaker 178 with the synchro-verifier adjusted for any particular desired characterlstics, the total resultant torque of the synchroverifier will be negative or in acontact opening direction. The contact 54 will, therefore,.- be rotated out of engagement with contacts 68 and the relay 197 -will be deenergized. The relay 197 is so designed and adjusted as to introduce a predetermined time delay in the operation thereof and thereby permit. the moving contact 54 of the synchro-verifier to berotated out of engagement incomplete andthe closing winding 252 of circuit breaker 178 is not energized to effect the closing of the breaker. This contact circuit is arranged by placing the contacts 208 of relay 197 in series with one of the contacts 221 of relay 208 and thence to one of the contacts 234 of relay 223.

It is obvious, therefore, that when the circuits 171 and 174 are energized, the synchro-verifier .contacts 68 must be bridged by the contact 54 bei fore the circuit breaker 176 is permitted to close,-

and, further, the synchro-verifier contacts must remain closed for a predetermined time, depending upon both the particular characteristics thereof and the time delay obtained by means of the relay 197, before the energizing circuit will be completed for the winding 246 of relay 247.

When the voltage of circuit 171 is properly related to the voltage of circuit 174 in magnitude, phase position, and frequency, as `required by the particularcharacteristics for which the synchroverier is adjusted, the synchro-verifier contacts 68 will be bridged by contact 54 with the result that the winding 196 of relay 197 is energized and the relay contacts 206 bridged by contact 205 after a predetermined time.

The contacts 221 of relay 208 are bridged by contact 218 and the contacts 234 of relay 223 are bridged by ycontact 232, the control energizing circuit being completed only by the closing of contacts 206 of relay 197.

The above-mentioned control circuit may be traced from the negative bus of source 244, through contacts 234 and contact 232 of relay 223, contacts 206 and contact 205 of relay 197, contacts 221 and contact 218 of relay 208, through energizing winding 246 of relay 247, resistance 248, push button switch 256 and thence to the positive bus of source 244. The relay 247 is therefore actuated to close contacts 249 by means of pallet switch 251 with the result that the energizing circuit for the closing coil 252 of the circuit breaker 178, is completed from the negative bus of source 244, through contacts 249 and pallet switch 251 of relay 247, through winding 252, and thence to the positive bus of the source 244. Upon the energization of the winding 252, the circuit breaker 178 is actuated to its closed position to connect the circuits 171and 174. 'Ihe holding circuit for relay 247 has been explained hereinbefore and is completed by the closing of contacts 253 by means of pallet switch 254. A push button arrangement 256 is indicated generically in the holding circuit of relay 247 and may be actuated when desired, -to effect the lopening of circuit breaker 178.

From the foregoing description of the operation of vthe arrangement 'of-Fig. 13, it may be concluded that thesynchronizing arrangement of the present invention may be combined with suitable relays to effect the connection of two .electrical circuits or systems when neither of the 'circuits are energized; when either one of the circuits -is' `eneizgizedand the other circuit de- A energized; and when both circuits are, energized Vio and the magnitude, phase position and frequency'v of the'two circuit voltages bear a predetermined relation.

Obviously, in the Fig.l3 arrangement,A the. synchro-Vernier could be adjusted for the characvteristics shownin Fig- 8 andthe necessity for the voltage relay 197 would not arise. With such an adjustment of the synchro-vender, the contacts 68 would normally be openbecause of the initial negative torque of the spiral control spring- 67 .effecting the rotation of contacts 54 out of engagement' with the contacts 68. In this case,

the contacts iii would replace the contacts 206 of relay 197 in thel control circuit hereinbefore described. V In the synchronizing arrangements shown in Figs. l2 and 13, it isobvious that the circuit "breaker, for connecting two systems, may be actuated to its closed position and latched by any suitable mechanical arrangementthereby obviating the .necessity of maintaining the closing coil energized. It is further apparent that any circuit breaker opening means may be employed.- such as a directional relay in the application of the present invention to alternatingf'c\n'rentv network systems of distribution.

` present invention thereof which may be'considered as being prop- One modification of the present invention has been described in detail and .the more genera!v applications thereof have been considered in order to better permit the proper application thereof. 'I'his invention is not to be limited to the lexact novel features disclosed because it is vobvious that in`view of the complete mathematical included inthe present specification, oneskilled in the art may eiectmany modincations of the and propose applications erly within' the'spirit and scope otl the present invention. v

It is desired, thereforathat no limitations be imposed uponthefpresent invention other than requil'ed by the prior art and as indicated in the appended claims,

. said elements for closing said switch under pre-v I cl'aim'as my invention:l 1. In combination with two alternating-current circuits and a switch for connecting said circuits,

control means for said switch including a'pair ofelectromagnetic elements arranged to produce opposing forces, means for energzing'each of said elements in accordance with line voltage conditions derived from-said circuits and difference voltage conditions determined by voltages across the break contaotsof said-switch, and means responsive to the difference of forces exerted by determined electrical conditions of said circuits.

2.: In combination-with two alternating-current circuits and a switch for connecting the circuits,

A-controlmeans for said switch including relay means and means for energizing said relay means -in vaccordance with the circuit voltages and the an opposed 75 difference voltage across the-break contacts of ,said switch, said relay means being adapted to produce a torque in accordance with one of the circuit voltages and the difference voltage and torque invaccordancewith the other` circuit voltage andthe-difference voltage.

- novatos 3.'In4 combination with two alternating-cur# vrent circuits and a switch for connecting the circuits, control means for said switch including relay means, meansfor eiiectively energizing said relay means in accordance with the voltages incident to said circuits only whensaid circuit'sare energized for eiecting the closing of said switch :under predetermined electrical conditions, and

means operatively associated with said nrst" means and said switch for effecting the closing of said switch when only one of said circuits is energized.

4. In combination with two alternating-current circuits'and a switch for connecting the circuits,

-control means for said switch including a plural element relay means connected and arranged to be energized in accordance withthe voltages incident to said circuits for effecting the closing of said switch only during predetermined phase and frequency relations between the two circuit voltages and means electrically associated with said control means and said switch for effecting the closing of said switch when only one of said circuits is energized.

5. In combination with two alternating-current circuits and a switch for connecting the circuits',

control means for said -switch including means connected and arranged to be effectively energized in accordance with the-voltages incident to said circuits only when said circuits are energized for effectingfthe closing of` said :switchl under ict predetermined electrical conditions, means operatively associated with said iirst mearxsand said switch for effecting the @105mg of said switch-- 7 110,

when only one of said circuits is energized and means associated with said switch and said contrclmeans for effectingthe closing of said switch when both of said circuits are de-energized.`

'8. In apparatus responslveto the condition of synchronism of a pair of alternating-current cir-'- cuits. 4a pair of watt-responsive elements and' a ance 'with the corresponding voltage condition of the other of said circuits, and means for energizing the remainingwinding of each of said ele-4 ments in accordance with the vector difference of said voltage conditions, the relative directions of said windings being such that the forces produced by said elements normally oppose.

7. In apparatus responsive to the condition of f synchronism of a pair of alternatingv-current'circuits, a pair of induction disc elements 'and a lmovable member responsive to the algebraic sum of the turques of said elements, each of said elements having a pair of windings .relatively posi-V tioned to produce a torqueproportional to ,the vector product of currents in said windings,

'140 means for energizing a winding of one'of said elements in accordance with a voltage vcondition of one of said circuits, means for energizing a' windingof the other of said elements in accord- 4ance with the corresponding voltage condition of the vother ofsaid circuits, and means for energizing the remaining winding of each ofsaidele- -ments l" mcordance with the vector difference ofsaid voi-lage conditions, the relative directions of- 8. In apparatus for automaticaliv synchronizing a pair o! alternating-current circuits, a switch for connecting' said circuits, a pair ci induction .disc elements and a movable member responsive in accordance with a cc Vto the algebraic sum of the torques o! said elements, each of said elementsliaving a pair of windings relatively positioned to produce a torque proportional to the vector-product of currents in said windings, means for energizing a winding of one of 'said elements in accordance with a voltage condition of one of said circuits, meansv for energizing a winding of the other of said elements kding voltage ccndition ci' the other of said circuits, ymeans for energizing the remaining winding of each of said elements in accordance with the vector dinerence switch to dose when ma voltage Iemulsions,-am in a predetermined relationship ot magnitude and phase position.

9. In apparatus responsive to the condition of synchronism of a pair o! alternating-currentcircuits, a pair of induction elements leach comprising a magnetic structure having a first magnetic vpole included in a iirst magnetic path and a second magnetic pole positionally displaced from said first magnetic pole and included in a second magnetic path, winding means inductively associated with each of said magentic structures and operable to produce time-displaced -fluxes in the poles thereof in response to voltage conditions derived.- from. said circuits, induction armature means subject to opposing forces produced by said elements, and means for adjusting the relative forces produced by said elements comprising o! said voltage conditions, the relative directions means for varying the reluctance of one of said .ct said windings being such that the yturques of paths. v l y said elements normally oppose, and means in- `iliILlZilAlid K. SONNEMANN.

cluding said movable member for causing said i miraban-,imag I iiKmSonncmann, Dallas, 'Teri lSrNcHrioNrz'iNqiSYs'rnM. 'Patentf v dated O'ctoe Westnghmise,

am i Manufact'ringf-Companyti V roo 

